title: Comparative proteomics reveal diverse functions and dynamic changes of Bombyx mori silk proteins spun from different development stages.
abstract: Silkworms (Bombyx mori) produce massive amounts of silk proteins to make cocoons during the final stages of larval development. Although the major components, fibroin and sericin, have been the focus for a long time, few researchers have realized the complexity of the silk proteome. We collected seven kinds of silk fibers spun by silkworm larvae at different developmental stages: the silks spun by new hatched larvae, second instar day 0 larvae, third instar day 0 larvae, fourth instar day 0 larvae, and fourth instar molting larvae, the scaffold silk used to attach the cocoon to the substrate and the cocoon silk. Analysis by liquid chromatography-tandem mass spectrometry identified 500 proteins from the seven silks. In addition to the expected fibroins, sericins, and some known protease inhibitors, we also identified further protease inhibitors, enzymes, proteins of unknown function, and other proteins. Unsurprisingly, our quantitative results showed fibroins and sericins were the most abundant proteins in all seven silks. Except for fibroins and sericins, protease inhibitors, enzymes, and proteins of unknown function were more abundant than other proteins. We found significant change in silk protein compositions through development, being consistent with their different biological functions and complicated formation.
authors.affiliation: State Key Laboratory of Silkworm Genome Biology, Southwest University , 216, Tiansheng Road, Beibei, Chongqing 400716, China.
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Dong
authors.forename: Ping
authors.initials: P
authors.lastname: Zhao
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianping
authors.initials: J
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Lin
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Xia
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D002853:Chromatography, Liquid; D004798:Enzymes / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D063990:Gene Ontology; D040901:Proteomics / Q000379:methods; D047011:Silk / Q000235:genetics / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D004798:Enzymes; D047011:Silk